Description

Input: an image file containing the raster graphics to clean (i.e. an image
defined as a classic rectangular lattice of square pixels).

Output: an image file containing the cleaned raster graphics.

The image filter relies on multiresolution analysis methods (Wavelet
transforms) that remove some scales (frequencies) locally in space. These
methods are particularly efficient when signal and noise are located at
different scales (or frequencies). Optional features improve the SNR ratio when
the (clean) signal constitute a single cluster of pixels on the image (e.g.
electromagnetic showers produced with Imaging Atmospheric Cherenkov
Telescopes). This library is written in Python and is based on the existing
Cosmostat tools iSAp (Interactive Sparse Astronomical data analysis Packages
http://www.cosmostat.org/software/isap/).

The PyWI library also contains a dedicated package to optimize the image filter
parameters for a given set of images (i.e. to adapt the filter to a specific
problem). From a given training set of images (containing pairs of noised and
clean images) and a given performance estimator (a function that assess the
image filter parameters comparing the cleaned image to the actual clean image),
the optimizer can determine the optimal filtering level for each scale.

a graphical user interface to visualize the filtering process in the wavelet
transformed space;

an Evolution Strategies (ES) algorithm known in the mathematical optimization
community for its good convergence rate on generic derivative-free continuous
global optimization problems (Beyer, H. G. (2013) "The theory of evolution
strategies", Springer Science & Business Media);

However, note that these only need to be installed if those particular features
are needed. PyWI will import even if these dependencies are not installed.

Installation

Using pip

Most major projects upload official packages to the Python Package Index.
They can be installed on most operating systems using Python standard pip
package manager.

Note that you need to have Python3.x and pip already installed on your system.

Warning

Users of the Anaconda python distribution should follow the instructions
for Anaconda install (see Using conda bellow).

Note

You will need a C compiler (e.g. gcc or clang) to be installed to
install some dependencies (e.g. Numpy).

Note

The --no-deps flag is optional, but highly recommended if you already
have Numpy installed, since otherwise pip will sometimes try to "help" you
by upgrading your Numpy installation, which may not always be desired.

Note

If you get a PermissionError this means that you do not have the
required administrative access to install new packages to your Python
installation. In this case you may consider using the --user option
to install the package into your home directory. You can read more
about how to do this in the pip documentation.

Alternatively, if you intend to do development on other software that uses
PyWI, such as an affiliated package, consider installing PyWI into a
virtualenv.

Do not install PyWI or other third-party packages using sudo
unless you are fully aware of the risks.

On MacOSX and Gnu/Linux

You can install PyWI using the following command (in a terminal):

pip install pywi --no-deps

As an alternative, you can install PyWI from the downloaded source code:

python3 setup.py install --no-deps

If PyWI is already installed on your system you can upgrade it with this command:

pip install --upgrade pywi

To uninstall PyWI, type:

pip uninstall pywi

On Windows

You can install PyWI using the following command (in a command prompt):

py -m pip install pywi --no-deps

As an alternative, you can install PyWI from the downloaded source code:

py setup.py install --no-deps

If PyWI is already installed on your system you can upgrade it with this command:

py -m pip install --upgrade pywi

To uninstall PyWI, type:

py -m uninstall pywi

Using conda

To install this package with conda run in a terminal:

conda install -c jdhp pywi

So far, the PyWI Anaconda package is only available for MacOSX.
A package for Linux and Windows will be available soon.

Note

Attempting to use pip to upgrade your installation of PyWI may result
in a corrupted installation.